Where have you gone, Jack Welch?

FORTUNE — I never thought I would feel sorry for Jack Welch, but now, I do. His op-ed piece in Wednesday’s Wall Street Journal, “I Was Right About That Strange Jobs Report,” strikes me as, well, strange.

Even though I rarely wrote about Welch when he was becoming a household name as chief executive of General Electric GE, I watched — and admired — the way he handled himself with the media. He even managed to get the last word on one of the rare occasions I wrote about him.

In 1999, after Welch announced that he’d retire in 2001, I wrote a Newsweek column saying we couldn’t close the books on Welch’s tenure at GE until after we’d seen how his successor performed — a contrarian piece that made some of my bosses nervous. Shortly after the piece ran, my home fax machine spit out the last thing I expected to see: a brilliantly crafted, handwritten note from Welch telling me I was right.

That display of grace and wit, on top of a previous episode that’s too inside-baseball to go into, turned me from someone who called him “Neutron Jack” (for all the U.S. jobs he vaporized) into an almost-fan.

But now Welch has lost his game. He’s not deft, he’s not graceful, he seems to have turned into a humorless guy with a chip on his shoulder.

Let’s look at Welch’s Journal column, which occupies some of the most highly coveted space in the media world. In it, he makes the same mistake he made last week, one that led to the end of his stint as a columnist at Fortune and at our competitor, Thomson Reuters.

Welch’s op-ed asserts, without a shred of evidence, that the Bureau of Labor Statistics cooked last week’s unemployment numbers in order to help President Obama’s reelection campaign. That’s the same thing he said in his Friday tweets that touched off the uproar among the chattering and political classes.

In the Journal, Welch goes on at almost wonkish length about the flaws in the BLS methodology. Well, duh. Those flaws, and others that he could have mentioned, are no secret. They’re one reason that many people, including me, put little stock in the numbers the bureau reports in a given month. The BLS numbers are sometimes just hinky, to use the technical term. (See my colleague Steve Gandel’s take.)

From having watched these numbers for years, as best I can tell, they’re hinky for Republicans and Democrats alike. But when the BLS numbers weren’t going Obama’s way, I didn’t hear mainstream Democrats complaining that the books were being cooked. For that matter, I didn’t hear Welch complaining then, either.

In his prime, Welch would have extricated himself from this mess by writing a column that made people think, and maybe smile. But all Welch did in his Journal column is whine, and dig himself deeper into the hole. It’s beneath his dignity.

Welch, who’s a fellow senior citizen of mine — I’m 67, he’s a decade older — has had a great run, both in corporate America and, for the past decade, in the world of commentary and opinion. It’s a shame that he didn’t quit while he was still totally ahead.